The charge of a blorvek has to be a number that divides exactly all the charges found, and the largest possible charge on a blorvek is the largest number that divides the five charges found for the drops. When you divide 4.42, and 2.21 you get whole numbers (2 and 1). But 2.21 does not divide exactly 7.74 and 4.98. You can find that 0.5525 is the largest number that divides the five numbers: 7.74 / 0.5525 = 14, 4.42 / 0.5525 = 8, 2.21 / 0.5525 = 4, 4.98 / 0.5525 = 12. So, the answer is 0.5525 * 10 ^ -16 C or 5.525 * 10^ -17 C. For the part b) you find that 5.81 / 0.5525 = 10.5, so this charge means that the charge value in the first part is not valid anymore. If you divide 0.5525 by 2 you will find the new largest value: 0.5525 / 2 = 0.27625. You can check that 5.81 / 0.27625 = 21. And the new largest value is 2.7625 * 10^ - 17 C.